This is the fourth motet of the cycle and its edition is also based on Librone 1 (ff. 165v–166r), where it was written by Scribe A.
Only a few copying mistakes were made by the scribe; for instance, he wrote ‘via’ instead of vita in T2 and switched the position of ‘nostra’ and ‘vita’, thus changing the sense of the sentence from ‘requies nostra, vita perennis’ to ‘vita nostra perennis’ in A. Other than that the spelling of Iesus varies as usual and also that of the adjective perennis (eternal) and of the word Christ (‘Christus’, ‘Cristus’).
The first section of this motet, which was sung to the Offertory, uses as its textual source the same Christological prayer as in the precedent three motets. Afterwards the author of this motet’s text, or better its ‘designer’, interpolated a text belonging to an entirely different liturgical genre, namely that of the Benedicamus tropes: the second section of the motet (from ‘Verbum patris’ to ‘domino’) is indeed a well-known trope used during the Christmas season. This usage of texts belonging to completely different liturgical genres (notice also the litany fragment) exemplifies the combinatory approach of several Milanese cycles.^[1]

^[1] See Eva Ferro, ‘“Old Texts for New Music”? Textual and Philological Observations on the Cycles “Salve Mater Salvatoris” and “Ave Domine Iesu Christe” from Librone 1’, in Motet Cycles between Devotion and Liturgy, ed. Daniele V. Filippi and Agnese Pavanello, Schola Cantorum Basiliensis Scripta, 7 (Basel: Schwabe, 2019), 189–218.